My invention relates to ball bats and similar implements. More specifically, it relates to a shock damper that can be quickly and easily attached to the end knob of a ball bat or similar implement to reduce the transmission of vibrations from the end knob to the users hands, to provide the user with an improved grip on the bat and to provide a reference for the user to grip the bat.
The familiar form of a baseball bat has a generally cylindrical, relatively large barrel portion at one end and a generally cylindrical, relatively small handle portion at the other end. The handle is terminated by an end knob or ring-like enlargement, which helps to prevent the handle from flying out of the batter's hand when the bat is swung. For improving gripping characteristics of handles of hollow bat structures, at least a portion of the handle has a grip, usually made of a wrap of leather or similar material or a thin sleeve of synthetic material which terminates at a point on the handle near the end knob. For baseball bats turned from wood stock, the end knob is formed as an integral enlargement at the end of the handle. For hollow bat structures of metal or other suitable materials, the end knob is formed with a plug or extension joined to the end of the handle. Such a plug or extension must have sufficient structural rigidity to maintain an effective connection with the handle of the bat and to withstand the severe mechanical shock and axial stress to which the end knob is subjected during normal use of the bat.
When a ball bat is submitted to an impact, like the striking of a ball, the bat vibrates. Whether the bat is wooden or is of hollow construction of metal or other materials, if the ball strikes the bat away from the center of the barrel, these vibrations can be relatively intense and cause an unpleasant, and sometimes even painful, sensation in the batter's hands often referred to as "bat sting." Some of the more unpleasant and painful of these vibrations are often transmitted through the end knob of the bat to the heel of the player's hand resting against the end knob as the player grips the handle. Moreover, end knobs with exteriors made of hard materials, such as wood or metal, make it more difficult for a batter to keep a good grip on the bat.
Over the years, some ball players have wrapped tape over the end knobs of ball bats to attempt to reduce bat sting and to improve their grip. However, tape is inconvenient to apply and remove and is relatively ineffective in reducing bat sting.
For bats of hollow metal construction, metal end caps have long been known, but failed to provide desired vibration dampening characteristics. See U.S. Pat. No. 3,703,290 (Nov. 21, 1972) to Wilson. A number of United States patents have disclosed bat end knobs composed of rubberous or homogeneous resiliently compressive material adapted to dampen vibrations in hollow bats. See U.S. Pat. No. 3,735,473 (Feb. 3, 1981) to Wilson. As noted above, however, such end plugs must have structural rigidity, which limits their vibration dampening capabilities.
U.S. Pat. No. 3,703,290 discloses a hollow metal ball bat construction using a composite knob end plug having an inner plug element composed of substantially rigid material and a partially exposed outer plug element composed of resiliently compressible material such as plastic or rubber, with polyvinyl chloride being preferred. As noted by Wilson, the dampening characteristics are improved as the outer plug element is made more compressible, but this tends to worsen wear resistance of the end knob.
Notwithstanding the previously known end knob constructions using resiliently compressible material, most hollow bats sold today have end knobs with a metal exterior used to form a secure mechanical joint with the handle of the bat. U.S. Pat. No. 4,248,425 (Feb. 3, 1981) to Easton et al. discloses a hollow bat structure having such an end knob. The end knob has a rigid exterior "skin" and an interior cavity. Positioned in the cavity is a compressed ring of resilient material, such as gum, plastic or rubber, for vibration dampening. Again, however, because the exterior of the end knob is rigid and is securely joined to the bat handle, the reduction of vibrations transmitted to the batter's hand from the end knob is not optimal. Moreover, it is more difficult for a batter to effectively grip such an end knob because it has a rigid exterior.
None of the end knobs described above can be quickly and easily removed from and replaced on the bat, for example, when the end knob is worn or damaged. Moreover, to the extent these end knob constructions provide vibration dampening, they do not apply to bats of solid wooden construction.
In addition to the above needs, it is sometimes desirable for a batter to "choke up" in gripping the handle of a bat so that the heel of the batter's lower hand is located on the handle some distance above the end knob of the bat. For example, a batter will often choke up to exercise better bat control during the batter's swing. To help train batters (particularly those who are young or are just learning how to bat) to choke up on the bat handle, it is desirable to provide a device to give the batter a reference point for locating his or her grip.
There remains, therefore, a need for a ball bat shock damper that provides improved vibration dampening and improved gripping characteristics and that can be quickly and easily placed on and removed from the bat. In addition, there is a need for a reference device for gripping a bat that provides vibration dampening and is easy to use.